Hermetic rotary compressor and refrigerating cycle device using the same

ABSTRACT

In a two-cylinder type hermetic rotary compressor, a first cylinder is always compressed and operated since a spring member biases a first vane. A pressure introducing pipe is connected to a second vane room arranged in a second cylinder. The second cylinder is stopped in operation and is operated by introducing sucking pressure or discharge pressure from the pressure introducing pipe. A discharge pressure introducing pipe connected to a portion of a hermetic case below the oil face of lubricating oil is connected to the pressure introducing pipe.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a hermetic rotary compressor having twocylinders and capable of changing performance by simultaneouslyperforming a compressing operation by both the cylinders andinterrupting the compressing operation in one of the cylinders andreducing a compressing work. The present invention also relates to arefrigerating cycle device using the hermetic rotary compressor.

2. Background Art

In the general hermetic rotary compressor, an electric motor section anda compressing mechanism section connected to the electric motor sectionare stored in a hermetic case. The compressing mechanism sectioncompresses a cooling medium gas, and once discharges the cooling mediumgas into the hermetic case. Thus, the interior of the hermetic case ishigh pressure. In the compressing mechanism section, a piston is storedto a cylinder room arranged in the cylinder. Further, a vane room isarranged in the cylinder, and a vane is slidably stored in the vaneroom. A tip edge of the vane is projected onto the cylinder room side,and is pressed and biased by a compression spring so as to elasticallycontact with the circumferential face of the piston.

Accordingly, the cylinder room is partitioned into two rooms along therotating direction of the piston by the vane. A sucking section iscommunicated with one room side, and a discharging section iscommunicated with the other room side. A sucking pipe is connected tothe sucking section, and the discharging section is opened to thehermetic case.

In recent years, a hermetic rotary compressor of a two-cylinder typehaving two sets of cylinders arranged vertically tends to becomestandard. In such a compressor, if a cylinder for always performing thecompressing operation and another cylinder capable of switchingcompression and stoppage in accordance with necessity are arranged, ausing performance range is enlarged so that it is advantageous.

For example, in Japanese Patent Unexamined Publication No. H1-247786, arotary compressor having two cylinder rooms is disclosed. In this rotarycompressor, a high pressure introducing section is provided. The highpressure introducing section compulsorily separates a vane of one of thecylinder rooms from a roller, holds the vane, and sets the cylinder roomto high pressure. The high pressure introducing section therebyinterrupts the compressing operation in accordance with necessity.

In this kind of the compressor, the vane is compulsorily separated fromthe piston and is held when the other cylinder room is compressed andoperated while the operation of one cylinder room is stopped. Therefore,a closing vane room is arranged on the rear face side of the vane.However, in this compressor, no vane room is communicated with theinterior of the compressor, and a so-called closing room is formed.Therefore, no lubricating oil retained within the hermetic case issufficiently supplied to a sliding portion of the vane so that wear,burning, etc. are generated.

SUMMARY OF THE INVENTION

The hermetic rotary compressor of the present invention is atwo-cylinder type hermetic rotary compressor. Since a spring memberbiases a first vane, a first cylinder is always compressed and operated.A pressure introducing pipe is connected to a second vane room arrangedin a second cylinder. The second cylinder is stopped in operation and isoperated by introducing sucking pressure or discharging pressure fromthe pressure introducing pipe. A discharging pressure introducing pipeconnected to a portion of a hermetic case below the oil face oflubricating oil is connected to this pressure introducing pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the longitudinal section of a hermetic rotarycompressor and the construction of a refrigerating cycle device inaccordance with an exemplary embodiment of the present invention.

FIG. 2 is an exploded perspective view of a first cylinder and a secondcylinder of the hermetic rotary compressor shown in FIG. 1.

FIG. 3 is an exploded perspective view of the second cylinder, anintermediate partition plate and a sub-bearing of the hermetic rotarycompressor shown in FIG. 1.

FIG. 4 is a cross-sectional view of a compressing mechanism section ofthe hermetic rotary compressor shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the sectional structure of a hermetic rotary compressor inaccordance with an exemplary embodiment of the present invention.Compressing mechanism section 2 is arranged in the lower portion of theinterior of hermetic case 1. Electric motor section 3 is arranged in theupper portion of the interior of hermetic case 1. Electric motor section3 and compressing mechanism section 2 are connected through rotatingshaft 4.

Electric motor section 3 is constructed by stator 5 fixed to the innerface of hermetic case 1, and rotor 6 arranged inside stator 5 through apredetermined clearance. Rotating shaft 4 is inserted to and fixed withrotor 6.

Compressing mechanism section 2 has first cylinder 8A and secondcylinder 8B in the lower portion of rotating shaft 4. Cylinder 8A andcylinder 8B are vertically arranged through intermediate partition plate7.

Main bearing 9 is overlapped with the upper face of cylinder 8A, and isfixed with cylinder 8A together with first valve cover 10A. Sub-bearing11 is overlapped with the lower face of cylinder 8B, and is fixed withcylinder 8B together with second valve cover 10B. Discharge ports ofcylinders 8A, 8B opening into hermetic case 1 are respectively arrangedin valve covers 10A, 10B.

Rotating shaft 4 is rotatably supported by main bearing 9 andsub-bearing 10. Further, rotating shaft 4 extends through the interiorof each of cylinders 8A, 8B, and is fixed to first eccentric portion 4Aand second eccentric portion 4B. Eccentric portions 4A and 4B are formedwith a phase difference of about 180°.

The detailed structure of cylinders 8A, 8B will next be explained.Eccentric portions 4A, 4B mutually have the same diameter, and arerespectively assembled so as to be located in the inside portions ofcylinders 8A, 8B. First eccentric roller 12A and second eccentric roller12B mutually having the same diameter are fitted to the circumferentialfaces of respective eccentric portions 4A, 4B. Eccentric rollers 12A,12B are connected to rotor 6 of electric motor section 3 throughrotating shaft 4. Namely, eccentric roller 12B is coaxially connected toelectric motor section 3 with respect to eccentric roller 12A.

In each of cylinders 8A, 8B, first cylinder room 13A and second cylinderroom 13B, and first groove 14A and second vane groove 14B communicatedwith cylinder rooms 13A, 13B are respectively arranged. Further, firstvane room 15A and second vane room 15B are arranged on the sidesopposite cylinder rooms 13A, 13B, of grooves 14A, 14B. Eccentric rollers12A, 12B are respectively eccentrically rotatably stored in cylinderrooms 13A, 13B.

Vanes 16A, 16B are stored in respective grooves 14A, 14B so as to befreely projected and recessed with respect to cylinder rooms 13A, 13B.Spring member 17 is stored in vane room 15A. Spring member 17 isinterposed between an end face of the rear side of vane 16A and theinner circumferential face of hermetic case 1. Spring member 17 as acompression spring gives elastic force (back pressure) to vane 16A, andmakes a tip edge of vane 16A in contact with eccentric roller 12A. Thetip edges of respective vanes 16A, 16B are formed in a semicircularshape, and come in line-contact with the circumferential walls ofeccentric rollers 12A, 12B of the circular shape irrespective of therotating angles of eccentric rollers 12A, 12B.

Vane room 15A and a rear end portion of vane 16A are communicated withthe interior of hermetic case 1. Therefore, vane room 15A and the rearend portion of vane 16A directly receive the pressure within hermeticcase 1. Namely, since vane 16A is slidably stored in vane room 15A, andthe rear end portion is located in vane room 15A, the pressure withinhermetic case 1 is directly applied.

On the other hand, vane room 15B is not communicated with the interiorof hermetic case 1, and forms a separate independent closing space. Thestructure of second vane room 15B will be explained by using FIG. 3.Closing lid portions 7A, 11A are provided in intermediate partitionplate 7 and sub-bearing 11, both fixed to cylinder 8B. Upper and loweropening portions of vane groove 14B and vane room 15B as portionsopening into hermetic case 1 in cylinder 8B are closed by fixing closinglid portions 7A, 11A to cylinder 8B.

FIG. 4 shows a cross-sectional view in a fixing state of intermediatepartition plate 7 and sub-bearing 11. Vane room 15B forming the closingspace is communicated with the exterior of hermetic case 1 throughpressure introducing pipe 18 arranged in the rear portion of vane room15B. Namely, pressure introducing pipe 18 is communicated with theinterior of vane room 15B. Vane room 15B and the rear end portion ofvane 16B receive pressure guided by pressure introducing pipe 18. Thetip of vane 16B (shown as broken line portion) is directed to cylinderroom 13B, and receives the pressure within cylinder room 13B. As aresult, vane 16B is moved from the large pressure side to the smallpressure side in accordance with largeness and smallness of the mutualpressure applied to the tip portion and the rear end portion thereof.

The operation and action of the compressor in accordance with thepresent embodiment will next be described. Discharge pipe 21 isconnected to an upper end portion of hermetic case 1. Discharge pipe 21is connected to accumulator 25 through condenser 22, expansion mechanism23 and evaporator 24. First sucking pipe 26A and second sucking pipe 26Bwith respect to compressor 50 are connected to the bottom portion ofaccumulator 25. Sucking pipe 26A extends through hermetic case 1 and aside portion of cylinder 8A, and is directly communicated with theinterior of cylinder room 13A. Sucking pipe 26B extends through hermeticcase 1 and a side portion of cylinder 8B, and is directly communicatedwith the interior of cylinder room 13B.

Discharge pressure introducing pipe 27 for introducing the dischargepressure within hermetic case 1 to vane room 15B is arranged on hermeticcase 1. Discharge pressure introducing pipe 27 is attached to the bottomportion of hermetic case 1. Further, sucking pressure introducing pipe28 is arranged so as to be branched from an intermediate portion ofsucking pipe 26B. Sucking pressure introducing pipe 28 is joined todischarge pressure introducing pipe 27 and becomes pressure introducingpipe 18 and is guided to second vane room 15B. First opening-closingvalve 29 is arranged on the upstream side from the joining portion ofdischarge pressure introducing pipe 27 to sucking pressure introducingpipe 28. Second opening-closing valve 30 is similarly arranged insucking pressure introducing pipe 28. Namely, valve 29 is arrangedbetween discharge pressure introducing pipe 27 and pressure introducingpipe 18, and valve 30 is arranged between sucking pressure introducingpipe 28 and pressure introducing pipe 18. Each of valves 29, 30 isconstructed by an electromagnetic valve, and is controlled so as to beopened and closed corresponding to an electric signal from controller31.

Thus, a pressure switching mechanism is constructed by dischargepressure introducing pipe 27 connected to vane room 15B, suckingpressure introducing pipe 28 and valves 29, 30. The sucking pressurefrom sucking pressure introducing pipe 28 or the discharge pressure fromdischarge pressure introducing pipe 27 is introduced to vane room 15B ofcylinder 8B in accordance with a switching operation of the pressureswitching mechanism.

Next, the operation of a refrigerating cycle device using hermeticrotary compressor 50 will be explained. First, when a normal operation(full performance operation) is selected, controller 31 opens valve 29and closes valve 30.

In cylinder 8A, vane 16A is always elastically pressed and biased byspring member 17. Therefore, the tip edge of vane 16A abuts on thecircumferential face of eccentric roller 12A, and the interior ofcylinder room 13A is divided into a sucking room and a compressing roomalong the rotating direction of eccentric roller 12A. Cooling medium gaswithin cylinder room 13A is then compressed as eccentric roller 12A isrotated. When rotating shaft 4 is continuously rotated, the coolingmedium gas attaining high pressure is discharged and filled withinhermetic case 1 through valve cover 10A, and is discharged fromdischarge pipe 21 at the upper portion of hermetic case 1.

At this time, since valve 29 is opened, the high pressure gas isintroduced from discharge pressure introducing pipe 27 to vane room 15Bvia pressure introducing pipe 18. On the other hand, cylinder room 15Battains a sucking pressure (low pressure) atmosphere. Thus, the tipportion of vane 16B attains a low pressure condition, and the rear endportion of vane 16B attains a high pressure condition. Therefore, vane16B is pressed and biased so as to come in slide contact with eccentricroller 12B. Thus, the tip edge of vane 16B abuts on the circumferentialface of eccentric roller 12B, and the interior of cylinder room 13B isdivided into a sucking room and a compressing room along the rotatingdirection of eccentric roller 12B. Cooling medium gas within cylinderroom 13B is then compressed as eccentric roller 12B is rotated. Namely,the compressing operation is performed in both cylinder rooms 13A and13B, and the full performance operation is performed.

Next, when a special operation (an operation for reducing compressionperformance by half) is selected, controller 31 closes valve 29 andopens valve 30. As mentioned above, the normal compressing operation isperformed in cylinder room 13A, and the interior of hermetic case 1 isfilled with the discharged high pressure gas and becomes high pressure.

Sucking pressure is introduced to vane room 15B through sucking pressureintroducing pipe 28. On the other hand, the sucking pressure is alsointroduced to cylinder room 15B via sucking pipe 26B and accumulator 25.Therefore, vane 16B is placed under a low pressure atmosphere in both ofthe front and rear end portions, and no differential pressure exists inthe front and rear end portions.

However, a rotating movement of eccentric roller 12B is made withincylinder room 13B. Therefore, vane 16B is compulsorily stored to vaneroom 15B by centrifugal force, and keeps a stopping state without makingthe movement in a position separated from the outer circumferential faceof eccentric roller 12B. Accordingly, no compressing operation isperformed in cylinder room 13B, and only the compressing operation incylinder room 13A is performed. Thus, hermetic rotary compressor 50 isoperated in performance reduced by half.

As mentioned above, it is possible to operate hermetic rotary compressor50 in two operating modes including the normal operation (fullperformance operation) and the special operation (performancehalf-reducing operation). Here, the high pressure gas introduced to vaneroom 15B in hermetic rotary compressor 50 is led out of the bottomportion of hermetic case 1.

Lubricating oil is always retained in the inner bottom portion ofhermetic case 1 irrespective of an operating state. Accordingly, thelubricating oil is guided to vane room 15B by the cooling medium gas ofhigh pressure at the normal operation (full performance operation).Accordingly, a sufficient amount of the lubricating oil is supplied tovane groove 14B, and no problem such as wear, burning, etc. of a slidingportion of vane 16B is generated. At the special operation (performancehalf-reducing operation), it seems that a low pressure gas is introducedto vane room 15B and the supply of the lubricating oil becomesinsufficient. However, at the special operation, no compressingoperation is performed in cylinder 8B, and the vane itself is at rest.Therefore, it is not necessary to consider wear, burning, etc.

It is not necessary to limit the attaching position of dischargepressure introducing pipe 27 to the bottom portion of hermetic case 1,but it is sufficient to set this attaching position to be located belowthe oil face of the lubricating oil during the operating time.

In recent years, a compressor using a hydrocarbon cooling medium and afluorohydrocarbon cooling medium including no chlorine is developed fromthe viewpoint of ozone layer protection. Such a cooling medium can bealso used in the compressor having this mechanism. Further, a compressorusing a natural cooling medium, such as carbon dioxide and ammonia, isdeveloped from the viewpoint of preventing the earth from warming. Thepresent invention can be also applied to the compressor using such anatural cooling medium.

In FIG. 1, cylinders 8A, 8B are vertically arranged on the lower side ofelectric motor section 3, but the present invention is not limited tothis construction. Cylinder 8A and cylinder 8B may be also arrangedvertically sandwiching electric motor section 3. Namely, it issufficient to arrange cylinder 8B in a position separated from cylinder8A within hermetic case 1. Further, in FIG. 1, electric motor section 3and cylinders 8A, 8B are arranged in the vertical direction, but thepresent invention is not limited to this arrangement. A hermetic rotarycompressor of a transversal arranging type for arranging these membersin the horizontal direction can be also arranged. In each of thesecases, it is sufficient to arrange discharge pressure introducing pipe27 below the oil face of the lubricating oil during the operating time.

Valves 29, 30 are constructed by an electromagnetic valve, but may bealso constructed by a valve of a manual type. In this case, nocontroller 31 is required. Further, in a joining position of dischargepressure introducing pipe 27 and sucking pressure introducing pipe 28, athree-way valve for switching connection from these introducing pipes topressure introducing pipe 18 may be also arranged instead of valves 29,30. The pressure switching mechanism can be also constructed by such anarrangement.

As mentioned above, in the hermetic rotary compressor in the presentinvention, wear of a sliding portion of the vane is prevented andreliability is improved. Accordingly, the present invention can be alsoapplied to uses such as a refrigerating air conditioner required to varyperformance over a wide range, a water heater using a heat pump, etc.

1. A hermetic rotary compressor comprising: a hermetic case forretaining lubricating oil in an inner bottom portion thereof; anelectric motor section arranged within the hermetic case; and acompressing mechanism section of a rotary type having: a first cylinderincluding a first eccentric roller connected to the electric motorsection, and a first cylinder room for eccentrically rotatably storingthe first eccentric roller, the first cylinder being arranged within thehermetic case; a first vane for dividing the first cylinder room intotwo portions along the rotating direction of the first eccentric roller,the first vane being arranged within the first cylinder and pressed andbiased so as to make a tip edge thereof abut on a circumferential faceof the first eccentric roller; a first vane room for storing a side endportion of the first vane, the first vane room being arranged on a sideopposite the first cylinder room with respect to the first vane; aspring member for pressing and biasing the first vane, the spring memberbeing arranged in the first vane room; a second cylinder including asecond eccentric roller coaxially connected to the electric motorsection with respect to the first eccentric roller, and a secondcylinder room for eccentrically rotatably storing the second eccentricroller, the second cylinder being arranged in a position separated froma position of the first cylinder within the hermetic case; a second vanefor dividing the second cylinder room into two portions along therotating direction of the second eccentric roller, the second vane beingarranged within the second cylinder and pressed and biased so as to makea tip edge thereof abut on a circumferential face of the secondeccentric roller; and a second vane room for storing a side end portionof the second vane, the second vane room being arranged on a sideopposite the second cylinder room with respect to the second vane;wherein cooling medium gas compressed in the compressing mechanismsection is once discharged into the hermetic case and the interior ofthe hermetic case becomes high pressure; the second vane is pressed andbiased when the cooling medium gas of sucking pressure is introduced tothe second vane room, and the second vane is separated and held when thecooling medium gas of discharging pressure is introduced to the secondvane room; and a discharge pressure introducing pipe as an introducingport of the high pressure cooling medium gas from the hermetic case tothe second vane room is arranged below an oil face of the lubricatingoil during an operating time.
 2. The hermetic rotary compressoraccording to claim 1, wherein the cooling medium is a chlorine freecooling medium.
 3. The hermetic rotary compressor according to claim 2,wherein the cooling medium is one of hydrocarbon and fluorohydrocarbon.4. The hermetic rotary compressor according to claim 2, wherein thecooling medium is a natural cooling medium.
 5. The hermetic rotarycompressor according to claim 4, wherein the natural cooling medium isone of carbon dioxide and ammonia.
 6. A hermetic rotary compressorcomprising: a hermetic case for retaining lubricating oil in an innerbottom portion thereof, and having a discharge pressure introducing pipearranged below an oil face of the lubricating oil during an operatingtime; an electric motor section arranged within the hermetic case; and acompressing mechanism section of a rotary type having: a first cylinderincluding a first eccentric roller connected to the electric motorsection, and a first cylinder room for eccentrically rotatably storingthe first eccentric roller, the first cylinder being arranged within thehermetic case; a first vane for dividing the first cylinder room intotwo portions along the rotating direction of the first eccentric roller,the first vane being arranged within the first cylinder and pressed andbiased so as to make a tip edge thereof abut on a circumferential faceof the first eccentric roller; a first vane room for storing a side endportion of the first vane, the first vane room being arranged on a sideopposite the first cylinder room with respect to the first vane; aspring member for pressing and biasing the first vane, the spring memberbeing arranged in the first vane room; a second cylinder including asecond eccentric roller coaxially connected to the electric motorsection with respect to the first eccentric roller, and a secondcylinder room for eccentrically rotatably storing the second eccentricroller, the second cylinder being arranged in a position separated froma position of the first cylinder within the hermetic case; a second vanefor dividing the second cylinder room into two portions along therotating direction of the second eccentric roller, the second vane beingarranged within the second cylinder and pressed and biased so as to makea tip edge thereof abut on a circumferential face of the secondeccentric roller; and a second vane room for storing a side end portionof the second vane, the second vane room being arranged on a sideopposite the second cylinder room with respect to the second vane; and apressure introducing pipe communicated with an interior of the secondvane room; wherein discharge ports of the first cylinder and the secondcylinder are opened into the hermetic case.
 7. A refrigerating cycledevice comprising A) a hermetic rotary compressor comprising: a hermeticcase for retaining lubricating oil in an inner bottom portion thereofand having a discharge pressure introducing pipe arranged below an oilface of the lubricating oil during an operating time; an electric motorsection arranged within the hermetic case; and a compressing mechanismsection of a rotary type having: a first cylinder including a firsteccentric roller connected to the electric motor section, and a firstcylinder room for eccentrically rotatably storing the first eccentricroller, the first cylinder being arranged within the hermetic case; afirst vane for dividing the first cylinder room into two portions alongthe rotating direction of the first eccentric roller, the first vanebeing arranged within the first cylinder and pressed and biased so as tomake a tip edge thereof abut on a circumferential face of the firsteccentric roller; a first vane room for storing a side end portion ofthe first vane, the first vane room being arranged on a side oppositethe first cylinder room with respect to the first vane; a spring memberfor pressing and biasing the first vane, the spring member beingarranged in the first vane room; a second cylinder including a secondeccentric roller coaxially connected to the electric motor section withrespect to the first eccentric roller, and a second cylinder room foreccentrically rotatably storing the second eccentric roller, the secondcylinder being arranged in a position separated from a position of thefirst cylinder within the hermetic case; a second vane for dividing thesecond cylinder room into two portions along the rotating direction ofthe second eccentric roller, the second vane being arranged within thesecond cylinder and pressed and biased so as to make a tip edge thereofabut on a circumferential face of the second eccentric roller; and asecond vane room for storing a side end portion of the second vane, thesecond vane room being arranged on a side opposite the second cylinderroom with respect to the second vane; wherein cooling medium gascompressed in the compressing mechanism section is once discharged intothe hermetic case and the interior of the hermetic case becomes highpressure; B) a condenser connected to a high pressure gas discharge pipeof the hermetic rotary compressor; C) an expansion valve connected tothe condenser; D) an evaporator connected to the expansion valve; E) anaccumulator connected to the evaporator and having a first sucking pipecommunicated with the first cylinder room and a second sucking pipecommunicated with the second cylinder room, the second sucking pipebeing branched to a sucking pressure introducing pipe; and a pressureswitching mechanism for switching pressure from the discharge pressureintroducing pipe and pressure from the sucking pressure introducingpipe, the pressure switching mechanism being for sending the switchedpressure to the second vane room.
 8. The refrigerating cycle deviceaccording to claim 7, wherein the hermetic rotary compressor further hasa pressure introducing pipe communicated with the interior of the secondvane room, and the pressure switching mechanism has a firstopening-closing valve arranged between the discharge pressureintroducing pipe and the pressure introducing pipe, and a secondopening-closing valve arranged between the sucking pressure introducingpipe and the pressure introducing pipe.